Implant devices for holding cells or tissue which secrete therapeutically useful substances are useful in a number of medical applications which include treatment of diabetes and gene therapy for treating cancer. Generally, the implant devices are manually loaded with cells or tissues and stored in saline or growth medium prior to implantation. At any point during the handling process, the exterior surface of the implant device may become accidentally contaminated with transplanted cells, tissues, or other materials. Contamination of an implant device may result from spillage of cell suspensions, handling the device with contaminated gloves or instruments, and leakage due to mechanical damage of the device. The presence of contaminating cells, especially transformed cells used in gene therapy applications, may function as sites for tumor growth. Accordingly, there is a need in the art for a method and apparatus which protect implant devices from accidental contamination of exterior surfaces and from mechanical damage during loading, storage, transportation and implantation.